SIGNAL TO NOISE RATIO OF THE SIGNAL SOUND AND ANNOUNCEMENT IN SUBWAY STATION

摘要

This study conducted survey and acoustical analysis for the signal sound and announcement in subway station. The results of survey showed that 82% of participants are dissatisfied with the signal sound and announcement. Acoustical characteristic and signal to noise ratio (S/N) of the signal sound and announcement were also analysed after measuring the signal sound, announcement, train arriving noise and background noise in concourses and platforms of four subway stations. In the concourse, S/N between announcement of escalator and background noise (BGN) ranged from -1.3 to 8.3 dB. In the platform S/N between sound signal for train arriving and BGN ranged from 4.9～13.8 dB, and S/N between announcement and noise of train arriving ranged from -14.4～1.4 dB. It was also found that S/N of the signal sound and announcement in separate platform was 2 dB higher than in island platform. S/N of the signal sound and announcement in platform with screen door was about 7 dB higher than platform without screen door.